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Atoms-in-Molecules Analysis


The atoms in molecules (AIM) theory is a model of quantum chemistry, which is based on the topological nature of the electron density scalar field to describe bonding in molecules. In addition to the bonding properties, AIM also divides the entire space based on topological features as well as bonding qualities, with each zone containing exactly one nucleus. By integrating within each region, a range of properties of a single atom can be obtained.

Alfa Chemistry provides its clients with professional AIM analysis services to solve their research problems by taking into account all design factors such as requirements, cost and delivery time. The atomic and group properties predicted by AIM agree with experimentally measured additive group contributions, and agreement with experiment is the only test of theory.

Our ServiceFig 1. AIM analysis of the critical point of the bond in the transition state structure of reaction 3 in the mechanism study of benzenethiol-catalyzed amide bond formation between thioester and primary amine. (Stuhr-Hansen N, et al. 2014)

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Alfa Chemistry uses the Multiwfn package for all quantum mechanical calculations. Topological analysis of real space functions is one of the important functions of Multiwfn. Topological analysis of electron density and its Laplace function is the core of AIM analysis, while topological analysis of ELF and LOL is used to analyze bond formation, aromaticity and other issues. There are also important applications. In Multiwfn these can be achieved through the main function 2.

Project NameAtoms-in-Molecules Analysis
DeliverablesWe provide our clients with IRC analysis results and all raw data.
Samples RequirementOur services require specific requirements from you.
Timeline DecideAccording to customers' needs
PricePlease contact us for an inquiry

Multiwfn's topological analysis function itself can map critical points and topological paths. But if you want to get more beautiful results, or to control the display more freely, you can export the analysis results from Multiwfn and draw them through the VMD program. VMD is a very flexible and powerful free molecular visualization software. Alfa Chemistry uses VMD version 1.9 here.

Intrinsic reaction coordinate (IRC) for the dyotropic interconversion of D / L -1,2-diphenyl-1,2-dibromoethane, computed at the B3LYP/6-311g level with a continuum solvent correction for benzene.Fig 2. The effect of intramolecular interactions on the Pirouetting motion in tetraalkyl succinamide rolane was investigated by AIM theory.. (Martins M.A.P, et al. 2017)

AIM restores the core operational concepts of the molecular structure hypothesis, i.e., atomic functional groups with additional and characteristic sets of properties, and the definition of bonds that connect atoms and give structure. Based on the topology of electron densities, AIM describes chemical bonds and the architectures of chemical systems. By splitting the space into atomic volumes with only one nucleus, which serves as a local attractor for the electron density, AIM enables the calculation of some physical parameters on an atom-by-atom basis in addition to bonding.

Our AIM analysis services significantly reduce costs, facilitate further experimentation, and accelerate the drug design process for our global customers. Our personalized, full-service approach will meet your innovative learning needs. If you are interested in our services, please feel free to contact us. We would be happy to work with you and see you succeed!


  • Stuhr-Hansen N, et al. (2014). "Mechanistic Insight Into Benzenethiol Catalyzed Amide Bond Formations from Thioesters and Primary Amines." Org. Biomol. Chem. 12(30): 5745-5751.
  • Martins M.A.P, et al. (2017). "Density Functional Theory and Quantum Theory of Atoms in Molecules Analysis: Influence of Intramolecular Interactions on Pirouetting Movement in Tetraalkylsuccinamide[2]rotaxanes." 17(11): 5845-5857.

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